OBJECTIVETo study the extent of distal intramural spread of distal 2 cm rectal carcinoma over the dentate line, and to improve quality of life for these patients through providing pathological evidence of operation mode choice.

METHODSSpecimens of thirty patients with rectal carcinoma, operated with ISR(intersphincter resection) or Miles procedure from May 2005 to July 2007, were collected, and their large and histology pathologic slices were examined. Specimens were dissected distally to the dentate line per 2 mm within 1cm and per 5 mm exceed 1cm. The length of distal intramural spread to rectal carcinoma was measured under light microscope.

RESULTSAmong the 30 specimens, distal intramural spread over the dentate line was observed only on one case and the invasion length over the dentate line was more than 2 cm, the invasion lengths of the other 29 cases were within the dentate lines.

CONCLUSIONDistal 2 cm rectal carcinomas seldom spread over dentate lines. Anus discomfortableness of these patients and other complications could be reduced through reserving more skin over the dentate line, which are important for the improving of quality of life in these patient.